title: NOD2 triggers PGE2 synthesis leading to IL-8 activation in Staphylococcus aureus-infected human conjunctival epithelial cells.
abstract: We previously showed that Staphylococcus aureus and Pseudomonas aeruginosa stimulate IL-8 expression in human conjunctival epithelial cells through different signal transduction pathways. As in some cell types both the bacteria may induce the release of prostaglandin E2 (PGE2) and PGE2 may affect the expression of IL-8, we aimed at investigating whether in human conjunctival cells infected with S. aureus or P. aeruginosa the activation of IL-8 transcription was mediated by PGE2 and which were the underlying molecular mechanisms. We found that S. aureus, but not P. aeruginosa, triggered IL-8 activation by increasing COX-2 expression and PGE2 levels in a time-dependent manner. Overexpression of nucleotide-binding oligomerization domain-2 (NOD2) resulted to be essential in the enhancement of IL-8 induced by S. aureus. It dramatically activated c-jun NH2-terminal kinase (JNK) pathway which in turn led to COX2 upregulation and ultimately to IL-8 transcription. The full understanding of the S. aureus-induced biochemical processes in human conjunctival epithelium will bring new insight to the knowledge of the molecular mechanisms involved in conjunctiva bacterial infections and develop novel treatment aiming at phlogosis modulation.
authors.affiliation: Department of Experimental Specialized Medical and Surgical and Odontostomatology Sciences, University of Messina, Messina, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Venza
authors.forename: Maria
authors.initials: M
authors.lastname: Visalli
authors.forename: Maria
authors.initials: M
authors.lastname: Cucinotta
authors.forename: Diana
authors.initials: D
authors.lastname: Teti
authors.forename: Mario
authors.initials: M
authors.lastname: Venza
mesh_terms: D002460:Cell Line; D003228:Conjunctiva / Q000276:immunology* / Q000382:microbiology; D003234:Conjunctivitis, Bacterial / Q000276:immunology*; D051546:Cyclooxygenase 2 / Q000096:biosynthesis / Q000235:genetics; D015232:Dinoprostone / Q000096:biosynthesis*; D004847:Epithelial Cells / Q000276:immunology / Q000382:microbiology; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics; D053473:Nod2 Signaling Adaptor Protein / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D011550:Pseudomonas aeruginosa; D013203:Staphylococcal Infections / Q000276:immunology*; D013211:Staphylococcus aureus; D015533:Transcriptional Activation
chemical_list: D016209:Interleukin-8; C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D015232:Dinoprostone
keywords: COX-2; Conjunctival epithelial cells; IL-8; NOD2; Staphylococcus aureus; c-jun NH(2)-terminal kinase